Action Tremors Research Paper

Due to the dopamine deficiency, PD patients have several different symptoms. Most report a gradual onset of aching, malaise, and fatigue; followed by evidence of a tremor in one or more than one extremity.11 Even with the large number of symptoms, no two people will experience the exact same symptoms of the disease.8 These symptoms are divided into two categories: motor and non-motor symptoms. Because PD affects the way the brain controls the movements of the body, the first symptoms usually identified are motor symptoms.12 Motor symptoms are the more visibly physical symptoms of PD.8 The four primary motor symptoms include tremor, bradykinesia, rigidity, and postural instability.13 Tremors are involuntary shaking resulting from contractions of opposing muscle
When voluntary movement is performed, it will briefly suppress. In advanced stages, an "action tremor" is more common. "Action tremors" are tremors that continue with movement. Tremors tend to be less severe the more the patient relaxes, or is unoccupied. The second cardinal sign of PD is Bradykinesia, which means "slow movement." This symptom is the result of inadequate recruitment of muscle force during initiation of movement. Being one of the most disabling symptoms of PD, patients experience longer reaction times, prolonged movements, and increased time on task.1 It is common for patients with bradykinesia to experience difficulty with repetitive movements and everyday functions.6 Rigidity is the third common sign of PD. Rigidity is the increased resistance to passive motion. Some patients complain of "stiffness" of their limbs when describing rigidity. There are two types of rigidity: cogwheel and lead pipe rigidity. O'Sullivan states, "Cogwheel Rigidity is a jerky, ratchet-like resistance to passive movement as muscles alternatively tense and relax. It occurs when tremor coexists with rigidity. Lead Pipe